The one thing we know for sure is that boys' brains are larger than girls', and girls' brains finish their maturation earlier.
The maturation can have important behavioural effects. Girls mature more quickly in self-regulation, self-control, inhibiting inappropriate impulses - the kinds of things that go awry in attention deficit disorder, which girls are diagnosed with less often.
You write that these small biological differences can grow into troublesome gaps between boys and girls. Which gaps worry you the most?
The verbal literacy gap for boys is certainly a concern. Writing, in which there is a larger gap, is something we need to address.
But what I am trying to get people to focus on is that learning how to read and write, regardless of our innate wiring, are learned skills and require massive amounts of practice, practice, practice. By being aware of the roots of literacy skills - mapping speech sounds onto letters, and rhyming - we'll do much better at promoting boys' language-arts skills than we will by talking about how they are hard-wired for this and that. That's my point.
What about the idea of separate schools or classrooms for girls and boys?
This idea that boys and girls learn differently is misleading. They clearly have different interests and somewhat different needs as far as physical movement. But the idea that the process of learning how to read or do arithmetic is fundamentally different for boys and girls is wrong and probably even dangerous.
There has been a big push for single-sex schooling. I spent a lot of time looking at the research, comparing single-sex schooling to co-ed education. It's not very compelling.
It is very difficult research to do, but the data we have thus far suggest if there is an advantage, it is for girls. The largest body of data from many countries - Canada, the U.S. Britain, Australia - suggests boys do not benefit from single-gender education compared with co-ed. It leads to the conclusion that both boys and girls do better with girls in the classroom, that girls sort of settle a classroom down and provide good role models.
Is there a crisis in the education of boys?
No. Boys are not reading more poorly. But with the college enrolment gap - and look at the number of girls on honour rolls - girls are outcompeting the boys, so it looks like boys are suffering in comparison.
So what can parents do? You write that it is a good idea for parents to offer boys experiences that build literacy skills and empathy, and to give girls a chance to improve spatial skills.
Knowing that children tend to play to their strengths, I think what we can do as parents and teachers is provide the cross-training that will benefit them later on. Learning is so cumulative; everything we know about the brain says the earlier you start the more successful you will be.
If we just let boys and girls kind of free-run for the first five or six years, we are going to get in a situation where boys are struggling more with reading and writing, and girls are not getting the spatial and movement experience that is important, both for later math and science.
It doesn't show up until you get to geometry, calculus and physics, but the roots of those abilities develop early and there is ample room for improvement through practice. So, getting girls involved in spatial activities through sports, through building toys, even video games, should help. What about expressing emotion?
We need to appreciate the roles we play in emotional training. Studies have shown parents do treat boys and girls differently and react differently to emotionality.
Girls are permitted to express fear and sadness more, but we don't accept anger in our daughters, and vice versa for boys.
One thing that everyone agrees is socially learned is that boys don't cry. Young boys cry plenty. They cry just as much as girls at least to age 2 and 3, but they are definitely trained through their parents, from their peers, that boys should not express emotion.
For some boys, I think that becomes a big problem. On the other hand, girls could benefit more from this lesson. If there is one thing that predicts clinical depression, it is girls' tendency to ruminate or indulge in their feelings and share them to the point where they become negatively reinforcing.
I think our attitudes are very important, and I think that as parents have become more enamoured of the hard-wired philosophy, the Mars-Venus notion, we can't help but unconsciously treat our boys and girls more differently than if we had a more egalitarian philosophy.
Anne McIlroy is The Globe and Mail's science reporter.